Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!van-bc!questor!sp From: sp@questor.wimsey.bc.ca (Steve Pershing) Newsgroups: sci.electronics Subject: Re: Caller ID info wanted Message-ID: Date: 14 Apr 91 19:43:58 GMT References: <41214@cup.portal.com> Organization: Questor - Free Internet/Usenet*Vancouver*BC::+1 604 681 0670 Lines: 26 dbell@cup.portal.com (David J Bell) writes: > More data acquired on Caller Number Delivery: > > The transmission occurs during the silent interval between > the first and second power ring signals, into an *ON HOOK* > line (no load, or >100k ohms). The signal is analog, phase- > coherent, frequency-shift keying, with a logic 1 (Mark) at > 1200 +/- 12 Hz, and logic 0 (Space) at 2200 +/- 22 Hz. The > transmission rate is 1200 bps, data is serial, binary, > asynchronous. Level is -13.5 dBm into 900 ohms. > > Looks a lot like a Bell 202 (1200 baud) half-duplex modem! I believe that Sierra Semiconductor have just announced a Caller-ID chip, costing around $2.00 in 100 quantities. --- Steve Pershing, System Administrator : The QUESTOR Project: FREE Usenet News/Internet Mail; Sci, Med, AIDS, more : :===========================================================================: : Internet: sp@questor.wimsey.bc.ca : POST: 1027 Davie Street, Box 486 : : Phones: Voice/FAX: +1 604 682 6659 : Vancouver, British Columbia : : Data/BBS: +1 604 681 0670 : Canada V6E 4L2 :